pH is a critical parameter that influences biochemical and environmental processes. Real-time and accurate pH detection is essential for monitoring health and the environment. Herein, a bacterial cellulose and methylacrylated chitosan (BC-MACS) composite hydrogel was prepared to achieve rapid pH detection. The integration of MACS reduced the crystallinity of pristine BC, with no adverse effects on thermal stability. SEM images validated the fibrous nature of the BC-MACS composite, indicating that MACS was successfully infiltrated into the pores of BC. By incorporating MACS into the BC matrix, the exceptional biocompatibility of BC was maintained, while simultaneously augmenting its mechanical properties. Due to the excellent swelling ability of MACS, the fabricated BC-MACS hydrogel exhibited superior swelling behavior compared to the BC hydrogel, which facilitated the absorption of the solution under test. A BC-MACS pH sensor was fabricated by introducing the pH indicator solution, and the color variation across the pH range (2–12) demonstrated a clear response to pH changes. Therefore, the BC-MACS pH sensor holds potential for use as a visual indicator in a diverse range of applications, especially for health and environmental monitoring.

Smart bacterial      cellulose–methylacrylated chitosan composite hydrogel: multifunctional      characterization for real-time pH monitoring. Polymers, 2025, 17: 914.      DOI: 10.3390/polym 17070914.